Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1757369AbXHBMFz (ORCPT ); Thu, 2 Aug 2007 08:05:55 -0400 Received: (majordomo@vger.kernel.org) by vger.kernel.org id S1757171AbXHBMF0 (ORCPT ); Thu, 2 Aug 2007 08:05:26 -0400 Received: from mail.suse.de ([195.135.220.2]:34108 "EHLO mx1.suse.de" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1756990AbXHBMFZ (ORCPT ); Thu, 2 Aug 2007 08:05:25 -0400 Date: Thu, 2 Aug 2007 14:05:24 +0200 From: Jan Blunck To: Erez Zadok Cc: Dave Kleikamp , Josef Sipek , linux-fsdevel@vger.kernel.org, linux-kernel@vger.kernel.org, Bharata B Rao , hch@infradead.org Subject: Re: [RFC 12/26] ext2 white-out support Message-ID: <20070802120524.GY5101@hasse.suse.de> References: <1185997941.18007.30.camel@kleikamp.austin.ibm.com> <200708012206.l71M6ai6028268@agora.fsl.cs.sunysb.edu> MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: <200708012206.l71M6ai6028268@agora.fsl.cs.sunysb.edu> Organization: SUSE LINUX Products GmbH, GF Markus Rex, HRB 16746 (AG Nuernberg) User-Agent: Mutt/1.5.16 (2007-06-09) Sender: linux-kernel-owner@vger.kernel.org X-Mailing-List: linux-kernel@vger.kernel.org Content-Length: 1626 Lines: 37 On Wed, Aug 01, Erez Zadok wrote: > There are three other reasons why Unionfs and our users like to have > multiple writable branches: > ... > And yes, it does make our implementation more complex. And error-prone and unflexible wrt to changes. When XIP was introduced, unionfs crashed all over this changes. I don't know if this has changed yet. Not speaking of other issues like calling back into VFS (stack usage), locking problems and so on. > 3. Some people use Unionfs in the scenario described in point #2 above, as a > poor man's space- and load- distribution system. Some of our users like > the idea of controlling how much storage space they give each branch, and > how much it might grow, and even how much CPU or I/O load might be placed > on each of the lower filesystems which serve a given branch. That way > they worry less about the top-layer's space filling up more quickly than > expected. Now Unionfs was never designed to be a load-balancing f/s (we > have RAIF for that, see ), > but users seems to always find creative ways to [ab]use one's software in > ways one never thought of. :-) And this has nothing to do with unioning ... > BTW, does Union Mounts copyup on meta-data changes (e.g., chmod, chgrp, > etc.)? No. But it was proposed during on of the last postings. - To unsubscribe from this list: send the line "unsubscribe linux-kernel" in the body of a message to majordomo@vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html Please read the FAQ at http://www.tux.org/lkml/